It is well known that one may prepare arylsulfonyl chlorides by replacement of a hydrogen atom on an aromatic compound by reacting the aromatic compound with chlorosulfonic acid. (See, for example, Romeo B. Wagner and Harry D. Zook, "Synthetic Organic Chemistry", John Wiley & Sons, New York, pp. 821-826 (1953); C. M. Suter, "The Organic Chemistry of Sulfur" John Wiley & Sons, Inc., New York (1944); R. C. Fuson, "Reactions of Organic Compounds" John Wiley & Sons, Inc., New York, pp. 42-43 (1962); U.S. Pat. No. 2,731,476; U.S. Pat. No. 3,299,103; U.S. Pat. No. 4,403,092; and U.S. Pat. No. 5,102,980.)
In general, the chlorosulfonation reaction has been carried out by using excess chlorosulfonic acid as the solvent and the aromatic sulfonyl chlorides have been isolated by drowning the chlorosulfonation reaction mixtures into ice or an ice/Water mixture. This is a difficult procedure because of the violent exothermic reaction of the excess chlorosulfonic acid with water, accompanied by copious quantities of hydrogen chloride and sulfur dioxide gas evolution. Further, on prolonged contact with the water, hydrolysis of the arylsulfonyl chloride may occur. Attempts to remove the water by drying may also result in hydrolysis. The resulting hydrolysis products, the arylsulfonic acids, are difficult to remove and may render the thus impure arylsulfonyl chlorides useless. For example, when the arylsulfonyl chlorides are used as in the functionalization of colored compounds to produce colored sulfonamides, which contain reactive polyester groups such as hydroxy, carboxy, carboxylic esters, etc., and which may be incorporated into the polyester by copolymerization with the diacid and/or diol during the polycondensation reaction (see, for example, U.S. Pat. No. 4,403,092, incorporated herein by reference), any remaining colored arylsulfonic acid may not be covalently bound to the polymer and may result in problems such as extractability, migration, etc. Further, we have observed that high levels of colored arylsulfonic acids present in the colored functionalized arylsulfonamides cause problems in the polymerization reaction in that only low molecular weight polymers are produced and high levels of diethylene glycol are observed when ethylene glycol is the selected diol, which is the preferred diol for most polyesters.
Finally, EP 0,289,952 describes the reaction of acetone with chlorosulfonic acid, preferably in the presence of a solvent, such as methylene chloride, for the reactants. No mention is made of utilizing ketones as a drowning medium for the chlorosulfonation reaction solutions such as described herein.